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bs412 lookahead

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This commit is contained in:
KubaPro010
2025-07-15 20:36:05 +02:00
parent 229ceff6d2
commit 6008d5e2e3
2 changed files with 13 additions and 1 deletions
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8
filter/bs412.c
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@@ -21,13 +21,19 @@ void init_bs412(BS412Compressor* mpx, float mpx_deviation, float target_power, f
mpx->target = target_power; mpx->target = target_power;
mpx->gain = 1.0f; mpx->gain = 1.0f;
mpx->max = max; mpx->max = max;
memset(mpx->lookahead_samples, 0, BS412_LOOKAHEAD);
mpx->lookahead_samples = 0;
#ifdef BS412_DEBUG #ifdef BS412_DEBUG
debug_printf("Initialized MPX power measurement with sample rate: %d\n", sample_rate); debug_printf("Initialized MPX power measurement with sample rate: %d\n", sample_rate);
#endif #endif
} }
float bs412_compress(BS412Compressor* mpx, float sample) { float bs412_compress(BS412Compressor* mpx, float sample) {
mpx->average += sample * sample * mpx->mpx_deviation * mpx->mpx_deviation; if(mpx->lookahead_counter > BS412_LOOKAHEAD) mpx->lookahead_counter = 0;
float process_sample = mpx->lookahead_samples[BS412_LOOKAHEAD-mpx->lookahead_counter]; // get sample from the other end
mpx->lookahead_samples[mpx->lookahead_counter++] = sample; // write to the first end
mpx->average += process_sample * process_sample * mpx->mpx_deviation * mpx->mpx_deviation;
mpx->average_counter++; mpx->average_counter++;
float avg_power = mpx->average / mpx->average_counter; float avg_power = mpx->average / mpx->average_counter;

6
filter/bs412.h
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@@ -5,10 +5,13 @@
#endif #endif
#include <math.h> #include <math.h>
#include <string.h>
#ifdef BS412_DEBUG #ifdef BS412_DEBUG
#include "../lib/debug.h" #include "../lib/debug.h"
#endif #endif
#define BS412_LOOKAHEAD 2048 // samples
typedef struct typedef struct
{ {
int mpx_deviation; int mpx_deviation;
@@ -20,6 +23,9 @@ typedef struct
float max; float max;
float gain; float gain;
double average; double average;
float lookahead_samples[BS412_LOOKAHEAD + 1];
int lookahead_counter;
} BS412Compressor; } BS412Compressor;
float dbr_to_deviation(float dbr); float dbr_to_deviation(float dbr);